A central station of a route guidance system collects traffic data from various points of a city area and updates aural routing information stored in roadside remote stations at periodic intervals. A moving vehicle senses the location of a roadside station to transmit a coded destination signal thereto where it is decoded to retrieve desired routing information. The latter is compressed in time dimension and transmitted back to the vehicle for storage in a storage device which is later retrieved at such a rate as to reproduce the original aural information.